Gov. Mark Dayton is siding with U.S. Steel in a battle over water pollution standards for the company's taconite facility in Mountain Iron.

In an interview with MPR News, Dayton said the existing sulfate standard aimed at protecting wild rice is out of date, and pushing it could be catastrophic for northeastern Minnesota.

As the Minnesota Pollution Control Agency prepares to release new environmental standards, U.S. Steel is lobbying the Legislature to delay the implementation of a clean water standard aimed at protecting water where wild rice grows.

The existing state standard prevents companies from discharging more than 10 milligrams of sulfate per liter of water. But company lobbyists and Iron Range legislators say the standard is too low. With his latest comments, his strongest to date on the long-running debate, Dayton is joining that group.

"Some people will say, 'you're going to abandon the standard,'" Dayton said. "But if the standard is obsolete and it's not validated by current science and information, then to stick with it and close down an industry isn't really well advised."

Dayton said the sulfate standard is outdated and has rarely been enforced since it was first established in 1973. U.S. Steel's Minntac plant was facing the new standard as it renewed a decades-old permit — something U.S. Steel said would cost hundreds of millions of dollars in upgrades.

Dayton cited a global slowdown in the steel industry as a factor in his decision. He said the sulfate standard is complex and doesn't guarantee that wild rice will thrive.

"If you have an impossibly low standard that doesn't correlate the problem that you're trying to solve anyway ... you put the whole industry out of business," he said. "We don't even know if it's going to improve wild rice conditions and it's going to be catastrophic for life up in northeastern Minnesota."

Chris Masciantonio, general manager of state government affairs at U.S. Steel Corp. (right), and U.S. Steel lobbyist Peder Larson speak to the Minnesota House Mining and Outdoor Recreation Policy Committee on Feb. 4, 2015.Tom Scheck / MPR News

Sarah Cassella, a spokeswoman for U.S. Steel, said in a statement that the company's position is that the standard should be based on sound science. She said company officials look forward to working with Dayton, the Legislature, local leaders and other stakeholders.

State Rep. Carly Melin, DFL-Hibbing, said she is pleased with Dayton's comments because she thinks the science behind the sulfate standard is outdated. Melin said making the standard more realistic would prevent taconite businesses on the Iron Range from spending hundreds of millions of dollars to update their facilities.

"We know that the industry just can't afford to make that sort of investment on the Iron Range," Melin said. "And obviously there are thousands of jobs depending on the taconite industry in northeastern Minnesota so it's really important to us that the regulations make sense. And we need to put a brake on this 10 standard and start looking at what the new scientific standard would be."

Dayton's comments seem to contradict the approach up until now by the Minnesota Pollution Control Agency. Last month agency scientists said its draft permits for the Minntac plant would require U.S. Steel to meet the existing sulfate standard. But agency officials said then that they would delay the permit to work on the wild rice standard.

Also last month, MPCA officials warned lawmakers that efforts to undermine the water pollution standards could prompt the federal Environmental Protection Agency to take control of state water regulations.

When asked about Dayton's comments, a spokesman for the MPCA said the agency will release its new wild rice recommendations this week. He wouldn't comment on U.S. Steel's permit because it will be revised after the new standards are established.

Environmental groups are not pleased that the governor has weighed in against the standard.

"We don't agree that it's out of date," said Kathryn Hoffman, an attorney with the Minnesota Center for Environmental Advocacy. "The science has been updated very recently and the science is strong and it's been peer reviewed by independent scientists."

She worries that state regulators and the Legislature may be preparing to ease the state's environmental standards just as the debate over copper-nickel mining in Minnesota is starting to get serious.

Hoffman said she hasn't seen any science that contradicts the current sulfate standard.

"If the governor is saying that there is some other scientific basis or some other studies that we haven't seen or these peer reviewers haven't seen then we'd like to know more about that," she said. "But we believe that all water quality standards are based on science and they can't be changed without a scientific basis."